Adjustable spring pivot for relay armatures



y 1950 P. CIBIE 2,509,724

ADJUSTABLE SPRING PIVOT FOR RELAY ARMATURES Filed March 25, 1947 spring d, fixed to the limb c.

Patented May 30, 1950 ADJUSTABLE SPRING PIVOT FOR RELAY ARMATURES Pierre Gibi, Paris, France Application March 25, 1947, Serial No. 737,166 In France September 6, 1946 4 Claims.

This invention relates to joints and it has for its object an improved adjustable joint, with spring, particularly applicable to the armature of the voltage regulators and like devices.

The arrangement according to the invention has essentially for its purpose to ensure a joint with a minimum of friction between the armature of an electro-magnet and the limbs thereof, while aifording a very great sensitiveness of adjustment of the withdrawing force exerted on the armature by the tension of its spring.

According to my invention, I provide an improved adjustable spring joint for a vibrating contact comprising an electro-magnet armature, a contact piece on the said armature, a flat spring, one end of which is rigidly secured to a limb of the said electro-magnet, a rigid member secured to the other end of the said spring, substantially parallel to the said armature, a threaded pin fixedly mounted on the said armature, passing through a hole at the end of the said rigid member, a nut on the said threaded pin, and a fixed contact member co-acting with the contact memher on the armature, the corner formed by the end of the rigid member secured to the spring and the said spring forming a hinge for the end of the armature opposite to that end carrying the first contact member.

The joint according to the invention ensures a great simplicity of assembly, as the armature is maintained in position only by the nut screwed on thethreaded pin, and its joint action is obtained simply by the resilience of the spring.

For the purpose of ensuring the greatest freedom of motion and the greatest sensitiveness of the adjustment the tension of the spring is preferably transmitted to the nut screwed on the threaded pin by means of a spherical surface on the nut seating on a corresponding spherical surface on the member carried by the spring.

Referring to the drawing, which shows, in the way of example only, a preferred manner of construction of the spring joint object of the invention, applied to the armature of a voltage regulator.

In the figure, a, is the armature intended to be attracted by the core I) and the limb c, of the electro-magnet, and which carries at its end the contact piece e, disposed opposite the fixed contact 1. These contacts e and 1 must be applied one against the other when the electro-magnet is not energised.

The articulation of the armature upon the limb c is here obtained by means of a fiat bent On the free extremity of this spring (1 is fixed a member g, bent so as to be substantially parallel to the armature. The armature a is connected to this member g by means of a threaded pin it suitably secured to the armature, on which fits a nut i resting on the member 9. The supporting surface of the nut i is preferably given a spherical shape adapted to rest on a corresponding spherical seating on the member 9, ensuring a perfect freedom of motion of the respective members, whatever may be the positionv of the piece g with respect to the armature. In this manner, the member 9 transmits to the armature a the tractive effort of the spring d, which tends to ensure the application of the contact e against the contact f.

In the inoperative position, that is to say when the electro-magnet is not energised, the spring d, owing to its initial tension, tends to lift the end of the member 9, causing this member to turn. Owing to the action of the knee-joint formed by the spherical co-acting surfaces of the nut i and its seat, the armature a is in this way subjected to a force F, the lever arm of which is Z, which has for its effect to press, on the one hand, the movable contact e on the fixed contact 3, and, on the other hand, the opposite end of the armature in the corner formed by the spring (1 and the end of the member g, this corner acting as a hinge.

It will be seen that, by screwing more or less the nut 2' on the pin h, the variation in the position of the member g will increase or reduce the bending of the spring d and therefore will, at the same time, vary the tension of this spring in a corresponding manner, thereby increasing or diminishing the force F exerted upon the armature.

When the electro-magnet is energised, the core I) attracts the armature a, with a force F the lever arm of which is Z which is greater than I so that it overcomes F and the armature a is lowered and separates the contacts e and I, while its other end remains in the corner formed by the spring d and the end of the member 9, acting as a hinge.

The initial adjustment of the tension of the spring by means of the nut i permits to adjust exactly the moment at which occurs the rupture of equilibrium between the forces F and F, that is to say the value of the voltage at which the breaking of the contact, and therefore the cutting-off of the current, must take place.

Owing to the fact that all joints are eliminated and that friction is rendered negligible, the arrangement just described has a very great sensitiveness and allows an extremely precise adjustment, and it is at the same time absolutely impossible for this adjustment to be upset. The simplicity of the construction of the arrangement and of its assembly, besides, allow of its economical manufacture.

It is understood that the details of construction which have been shown and which have been described above do not limit the invention in any way and may be varied without departing from the spirit of the invention as defined by. the'claims.

It must also be well understood, particularly, that, although the arrangement object of the invention has been shown and described more particularly in its application to a' voltage regulator, it can be similarly used for all similar arrangements using a vibrating contact of the same kind.

What I claim is:

1. An armature for an electromagnetic device of the type wherein the armature is movably supported on a stationary part of the magnet so as to effect the engagement and disengagement of two contact elements by its movement, comprising in combination, a leaf spring to be secured to said stationary part of the electromagnet, one end of said leaf spring being bent out of its central plane; a rigid arm secured to said bent portion of said leaf spring and extending at an angle therefrom; a rigid armature plate; a contact element fastened immediately to said armature plate;. and means for adjustably supporting said armature plate from said rigid arm in a position generally parallel to said arm and in lateral abutment with said leaf spring whereby said leaf spring may be placed under tension.

2. An armature for an electromagnetic device of the type wherein the armature is movably supported on ,a stationary part of the magnet so as to' effect the engagement and disengagement of two contact elements by its movement, comprising in combination, a leaf spring tobe secured to said stationary part of the electromagnet, one end portion of said leaf spring being bent out of its central plane; a rigidarm secured to said bent portion of said leaf spring and extending at an angle therefrom; a transverse opening in said arm; a tap ,bolt extending through said opening and freely slidable therein; a nut screwed onto one .end of said tap bolt and bearingv with a rounded surface against the edge of said opening in said arm; and a rigid armature plate secured erally parallel to said arm and in lateral abutment with said leaf spring whereby said leaf spring may be placed under tension.

3. In an electromagnet, in combination, a stationary magnet portion; a leaf spring secured at one end to said stationary magnet portion, the other end of said leaf spring projecting from said stationary magnet portion and being bent out of the central plane of the leaf spring; a rigid arm secured to said bent portion of said leaf spring and extending at an angle therefrom; a rigid armature plate; and means for adjustably supporting said armature plate from said rigid arm in a position generally parallel to said arm to the other end of said tap bolt in a position genverse opening in said arm; a tap bolt extending v through said opening and freely slidable therein; a nut screwed onto one end of said tap bolt and bearing with a rounded surface against the edge of said opening in said arm; a rigid armature plate secured to the other end of said tap bolt in a position generally parallel to said arm and in lateral abutment with said leaf spring whereby said leaf spring may be placed under tension.-

PIERRE CIBIE.

REFERENCES CITED 7 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,302,817 Leonard May 6, 1919 1,311,459 Patten July 29, 1919 1,576,768 Loudon Mar. 16, 1926 1,591,133 Kent July 6, 1926 1,764,375 White June 17, 1930 1,886,273 Thomson Nov. 1, 1932 1,979,709 Schaelchlin Nov. 6, 1934 2,253,483 Menzel Aug. 19, 1941 2,426,253 Towner Aug. 26, 1947 

